Andrew B. Cecala

Substantial Time Savings Achieved Through Computer Dust Analysis

Abstract This article describes a computer analysis system used presently by the Bureau of Mines to analyze quickly and accurately large volumes of information obtained from real-time dust monitors during research studies. It substantially reduces the time necessary to perform various data analysis calculations and manipulations including graphics. It also provides raw data files that can be transferred to other software packages for other required manipulations. A major benefit of the computer analysis system is the availability of information at the end of each test day. Onsite analysis makes it possible to modify a study during the field evaluation process. The system does not alter the data collection process, other than requiring a small data logger instrument to be connected to each dust monitor. In some cases, the system has reduced manpower requirements during the data gathering phase. The system reduces the analysis time required by previous methods while improving many aspects of the data evalua...

Reducing Bag Operator's Dust Exposure in Mineral Processing Plants

Abstract The Bureau of Mines has been investigating various techniques to reduce dust exposures of workers at mineral processing plants. A major problem has been the exposure of the bag operator who loads mineral product into 50- or 100-pound bags at a fill station. In many cases, this worker has the highest dust exposure of the entire plant. In the past few years, the Bureau has investigated several approaches that can significantly lower bag operator dust exposure. These include bag valve modification, dual bag nozzle system, overhead air supply island (OASIS), and control of background dust sources. Five commercially available bag-filling valves were evaluated to determine their dust reduction capabilities. An extended polyethylene valve was found to be the most effective, resulting in a 62 percent reduction in operator dust exposure as compared to the standard paper valve. A dual bag nozzle system was developed that decreases product loss and significantly lowers the operators exposure. With this sys...

Reducing Respirable Dust Exposure of Workers using an Improved Clothes Cleaning Process

A quick, safe, and effective method has been developed that allows workers to clean their dust laden work clothing periodically throughout the day. For the raining industry, this technique is much more effective than the current federally approved method of using a vacuuming system. This newly designed method is relatively inexpensive and can be easily installed at any operation to allow woriccrs to clean their clothing without contaminating the worker, the work environment, or co-workers to elevated respirable dust levels. This clothes cleaning process uses an air spray manifold to blow dust from a workers clothing in an enclosed booth, which confines the dust for capture and removal by a baghouse dust collector. Since the air exhausted by the dust collector causes the booth to be under negative pressure, no measurable quantities of dust were ever measured escaping from the booth to contaminate the work environment and/or other workers. The worker performing the cleaning process is required to wear a half-mask fittested respirator with an N100 filter, hearing protection, and full seal goggles_ Dust samples taken irtside the respirator of test personnel performing the clothes cleaning process showed very minimal to no respirable dust. This clothes cleaning process was performed in less than 20 seconds and was significantly cleaner than either the federally approved method of vacuuming, or the most common method of using a single compressed air hose. ft was also determined during this research that polyester-cotton blend coveralls clean more effectively than coveralls which are 100 percent cotton. The newly designed clothes cleaning process has potential application to any industry where workers clothing becomes contaminated with most any type of dust or product.

Gainsharing: A technique to improve management-employee relations and mine productivity

Abstract The intent of this article is to discuss a potentially cost-effective means of increasing mine production through improved management-employee relations. This article will specifically examine one particular technique—gainsharing. This involves two fundamental elements. The first is a working committee of personnel from the workforce and management whose primary purpose is to evaluate suggestions from employees on ways of improving the work or production process. An additional and equally important objective is to develop a trusting relationship between the employees and management through this two-way communication network. The second element of the gainsharing technique is a bonus plan in which employees are paid a bonus based on the amount of production increase over a base level for a prescribed time period. The key to a successful gainsharing plan, or to any other human factor management program or technique, is to establish a trusting and open relationship between employees and management. This technique must be “a way of life” for management and not just an attempt to increase productivity. The gainsharing plan is an excellent initial technique for developing this trusting relationship because it develops a communication network which shows employees that they have an input into the companys success, and that management is willing to listen and reward them as a group for their ideas and efforts.

Methane and dust controls for headgate cutouts

Abstract The headgate cutout is an area of concern for all retreating longwall mining operations. Because of the equipment and activities located in the headgate area, along with the ventilation flow pattern, methane and dust levels recorded at the shearer during the cutout are higher than for any other phase of the longwall mining cycle. This report presents several different techniques found by the Bureau of Mines over the past few years to successfully lower methane and dust levels during the headgate cutout for retreating longwall sections using antitropal ventilation (headgate to tailgate). Each of these techniques improves the health and safety of longwall workers and is economically feasible.

Design, testing, and modeling of environmental enclosures for controlling worker exposure to airborne contaminants

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Reducing workers' dust exposure during bag stacking in enclosed vehicles.

The Bureau of Mines has evaluated cost effective systems to ventilate enclosed vehicles being loaded directly with bagged product material at mineral processing plants. This evaluation included both forms of transportation: railcars and trailer trucks. The goal of this research was to lower the dust exposure of workers stacking bags in these enclosed vehicles; these workers usually have the highest dust exposures in the entire processing plant. The problem occurs because there is no mechanical ventilation inside these vehicles. As the vehicle is being loaded, dust concentrations increase to substantial levels because released dust has no means of exiting the vehicle or of being diluted with fresh air. In cases where the dust is hazardous, as with silica sand, this may present a serious health hazard. This research project was a two-step effort. The first step was a qualitative laboratory evaluation performed in a railcar to compare different types of ventilation systems (blowing, exhaust, and push-pull systems) using a methane (CH4) tracer gas technique. An exhaust system located over the snake conveyor was the most effective system at reducing gas levels in and around the bag stackers work area. The second step then involved a field evaluation at a silica sand processing plant to determine the systems effectiveness in the actual work environment. Three different versions were evaluated in an attempt to optimize the exhaust ventilation systems effectiveness. The most effective version involved exhausting 54.5 m3/min (2000 ft3/min) through a fiberglass tube located 1.1 m past the end of the slinger at a 2.0-m height so as not to interfere with the bag stackers job function.(ABSTRACT TRUNCATED AT 250 WORDS)